Third to e



(No Model.)

- W. B. LUOE/ ELEOTRIG ARC LAMP.

No. 507,916. Patented Oct. 31,1893.

W WITNESEEEI w NVENTCIR 5 UNIT D ST TES PATENT, OFFICE.

WILLIAM B. LUCE, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR OF ONE- THIRD TOE. S. RITCHIE dz SONS, OF SAME PLACE ELECTRIC-ARC LAM P.

SPEGIFICATIOIT forming part of Letters Patent No. 507,916, dated October31, 1893.

Application filed November 26, 1892. Serial No. 453,204. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM B. Luca, of Brookline, in the county ofNorfolk and State of Massachusetts, have invented certain new and usefulImprovements in Electric -Arc Lamps, of which the following is aspecification.

This invention relates to electric arc lamps and has for its object toprovide the same with a feed mechanism of novel construction as will bedescribed, for the upper carbon.

The invention has special reference to a feed mechanism in which afriction mechanism is operatively connected to the upper carbon, so thatwhen the current is established through the lamp, the friction feedmechanism is operated to move the upper carbon in an upward directionand when the resistance in the main circuit becomes abnormal, by reasonof an increase in length of arc, the friction mechanism is operated topermit the upper carbon to feed downward to again establish an arc ofnormal resistance.

The invention consists in the novel features of construction and.combinations of parts which will be fully described hereinafter andpointed out in the claims.

Figure 1 represents an elevation partially broken out, of a sufficientportion of an electric arc lamp embodying my invention to enable it tobe understood,the friction mechanism being shown in position toestablish the arc; Fig. 2 a partial elevation and section of the lampshown in Fig. 1, the friction mechanism being shown in the position itoccupies when the lamp is not in operation, and Fig. 3 a detail to bereferred to.

The lamp frame, which may be of any desired or usual construction, isherein shown as composed of a top plate a, a bottom plate a andintermediate rods or standards a forming said plates.

The lamp is provided with a low resistance solenoid a and a highresistance solenoid a having their cores 0. a pivotally connected to alever or walkingbeam a loose on a shaft a having hearings in suitablestandards or uprights a", only one of which is shown, the said standardsbeing shown as secured to the bottom plate a by screws a The shaft orhas mounted on it one member of a friction feed mechanism, shown as adisk or wheel 1), the other member of the said friction feed mechanismbeing shown as a strap or band I) having one end secured to the lever aas at b and its other end fastened to one end of a coil spring b theother end of which is connected to the top plate a, it being shown asfastened to an adjusting screw 6 The friction feed mechanism isoperatively connected to the upper carbon 17 of the lamp as will now bedescribed. The upper carbon 6 is secured as by set screw b to a carbonholder, shown as a tubular socket b secured to or forming part of an armor extension 19 of a sliding collar 17* fitted loosely on a column orguide rod or tube b herein shown as depending from the bottom plate a;the said guide rod or tube b being preferably made polygonal in shape toprevent the sliding collar b from turning on the said rod or tube,thereby insuring correct position of the upper carbon with relation tothe lower carbon c. The arm or extension b has attached to it one end ofa flexible connection such as a chain, cord or rope 19 preferably asprocket chain, which is passed over a sprocket wheel 5 on the shaft aand preferably over-a loose pulley or wheel I) mounted in uprights 6secured to the bottom plate a, the said chain or rope having secured toits other end, a counter balancing weight 19 which is suspended withinthe hollow guide or column b The hollow guide or column 19 as hereinshown has secured to it an arm or extension 0 to which the holder forthe lower carbon 0' is secured, the said holder being shown as a tubularsocket c fastened as by the screw 0 to two disks 0 c of insulatingmaterial which are fitted into an annular ring or loop 0 on the arm 0,the screw serving to secure the lower carbon holder 0 and the said disksto the arm 0 and also to electrically connect the lower carbon holder tothe negative binding post 0 of the lamp, the said screw being joined tothe said binding post by wire 0 The positive binding post 0 hasconnected to it one end 0 of the coil of the solenoid a the other end 0of which is joined to the frame of the lamp, it being shown as connectedto one of the rods or standards 0. The positive binding post 0 also hasconnected to it one end of the high resistance coil a, the other end 0of which is connected to the negative binding post 0 In operation, theparts of the lamp occupy the position shown in Fig. 2, when the currentis cut oil? from the lamp, but when the current is supplied to the lamp,the core a is attracted by its solenoid a and the lever d is turned onits pivot or shaft a and the band or strap 1) at the beginning of themovement of the lever 60' is engaged with the disk or wheel b, so that,on the continued movement of the core a and lever a the disk I) and itsshaft a are turned in the direction indicated by arrow 20, and

the upper carbon is lifted by the movement of the sprocket wheelassisted by the weight 12 \Vhen the resistance in the main circuitbecomes abnormal, the solenoid 0t becomes active and attracts its corea, thereby moving the lever back toward its normal position shown inFig. 2 until a pin or lug d on the strap Z) comes in contact with astop, shown as an arm at secured to one of the standards a and on thefurther movement of the lever a the friction strap or band I) is removedfrom engagement with the disk I), and the carbon holder is free todescend by gravity to feed the upper carbon toward the lower carbon.

In practice, the action of the friction feed mechanism is substantiallysensitive and the arc is maintained substantially constant after it hasonce been established, whereby a substantially steady light is obtained.

The lamp herein shown may be provided with a cut-out of any usualconstruction and not herein shown,

By means of the hollow guide rod or tube Z2 and the weighted flexiblechain extended into it, the lamp may be made more compact and the workrequired of the lamp trimmers lessened by doing away with the usual rodor tube for the upper carbon now commonly found in lamps as nowconstructed.

I claim 1. An electric arc lamp, comprising in its construction thefollowing instru mentalities, viz: a low resistance solenoid providedwith a core, a high resistance solenoid having a core, a lever pivotedintermediate of its ends and connected on opposite sides of the pivotwith said cores respectively, a toothed wheel whose center of rotationis coincident with the fulcrum of the lever, a disk or drum rotatablewith said wheel, a movable carbonholder for the upper carbon, a flexibleconnection by which the said holder is suspended and which passes overand is engaged by the toothed wheel, and a brake in the form of a strapor band fastened at one end and ar ranged to engage the periphery of thedisk or drum, its other end being connected with the lever,substantially as described.

2. An electric arc lamp, comprising III ItS construction the followinginstrumentahtres, viz: a low resistance solenoid provided with a core, ahigh resistance solenoid having a core, a lever pivoted intermediate ofts ends and pivotally connected at its ends with said coresrespectively, a toothed wheel whose center of rotation is coincidentwith the fulcrum of the lever, a disk or drum rotatable with said wheel,a movable carbon-holder for the upper carbon, a flexible connection bywhich the said holder is suspended and which passes over and is engagedby the toothed wheel, a brake in the form of a strap or band connectedat one end with a retractor and at the other end with the lever andarranged to engage the periphery of the disk or drum, and a fixed stopfor the said band or strap to encounter, substantially as and for thepurpose described.

3. An electric-lamp, comprising in its construction a polygonal hollowcolumn or guiderod, a sliding collar engaging said column and having anarm or extension constructed to hold the upper carbon, and acounterbalancing weight occupying the hollow column and connected withthe said arm or extension.

In testimony whereof I have signed my name to this specification, in thepresence ot two subscribing witnesses, this 19th day of November, A. D.1892.

WILLIAM B. LUO E.

Witnesses:

O. F. BROWN, A. D. HARRISON.

